Asphalt-surfaced roadways are built to facilitate vehicular travel. Depending upon usage density, base conditions, temperature variation, moisture levels, and/or physical age, the surfaces of the roadways eventually become misshapen and unable to support wheel loads. In order to rehabilitate the roadways for continued vehicular use, spent asphalt is removed in preparation for resurfacing.
Cold planers, sometimes also called road mills or scarifiers, are used to break up and remove layers of an asphalt roadway. A cold planer typically includes a frame propelled by tracked or wheeled drive units. The frame supports an engine, an operator's station, a milling drum, and conveyors. The milling drum, fitted with cutting tools, is rotated through a suitable interface with the engine to break up the surface of the roadway. The broken up roadway material is deposited by the milling drum onto the conveyors, which transfer the broken up material into haul trucks for removal from the worksite. As haul trucks are filled, they are replaced with empty haul trucks. The filled trucks transport the broken up material to a different location to be reused as aggregate in new asphalt or otherwise recycled. This transport process repeats until the milling process is finished.
Operators may wish to coordinate the timely arrival of empty haul trucks at the milling site with the pace of the milling process in order to improve the overall efficiency of the operation. On one hand, having too few empty trucks at the milling site can lead to increased down time when an operator must stop the cold planer to wait for an empty truck to arrive. On the other hand, too many empty trucks at the milling site can result in the wasteful under-utilization of resources. Cold planer operators typically communicate with a truck dispatcher at a material processing plant in an attempt to coordinate the movement of trucks to and from the jobsite. However, calls to the dispatcher from jobsite personnel may not always provide the dispatcher with enough information or enough time to efficiently coordinate movement of the trucks to and from the jobsite. Accurate, real-time measurement of the amount of asphalt reclaimed by the milling process of a cold planer is also desirable as a method to ensure that each individual hauling truck is not overloaded. Overloading of haul trucks may lead to violations of government regulations on maximum allowable loads for transport along public roads, as well as premature wearing of the haul trucks.
One attempt to monitor the production of a milling machine is disclosed in U.S. Patent Application Publication No. 2008/0216021 A1 of Berning et al. that published on Sep. 4, 2008 (“the '021 publication”). In particular, the '021 publication discloses a system for monitoring the operating parameters of the milling machine, the loading of a haul truck, and the surfaces in front of and behind a milling rotor of the milling machine. The system includes a number of sensors configured to measure operating parameters, including ambient conditions, engine parameters, and the position of a number of actuators that are configured operate tools and implements of the milling machine. The system also includes a number of cameras configured to observe the loading of milled material into a haul truck via a conveyor system, an unmilled surface in front of the milling rotor, and a milled surface behind the milling rotor. A processing unit transmits data from the sensors to a memory for data storage, as well as to a display in an operator station of the milling machine. A number of switches associated with the display allow the operator to select which parameters and camera feeds to observe on the display while operating the milling machine. The processing unit can establish a remote data transmission connection in order to communicate data from the sensors and cameras with a control center or another machine.
While the system of the '021 publication may allow for the observation of some milling parameters, it may not be optimum. In particular, information transmitted by the system of the '021 publication may not always provide accurate, real-time information. Further, the cameras may only allow for the observance of qualitative information, which may not be quickly and/or easily analyzed by offboard entities for other purposes. A lack of an accurate, real-time measurement of the actual conveyor belt speed in the conveyor system that transports milled and reclaimed asphalt material from the milling tool of the cold planer to the hauler truck also restricts the ability of existing systems to monitor the precise amounts of material being dumped into the hauler truck.
The disclosed system and method for managing the speed of a cold planer conveyor belt solves one or more of the problems set forth above and/or other problems in the art.